JPH09246904A - Surface mounted crystal resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the secular change of a frequency by supporting and fixing the side of both short sides of a crystal piece in a rectangular shape by the electrically conductive adhesive material of an Si group or the like, hermetically joining a cover to a terminal member by an inorganic material and forming a container whose inner part is evacuated. SOLUTION: The crystal piece is supported and fixed on both sides, the long side direction of the crystal piece 6 is turned to a Z axis and both end side parts composed of an X axis orthogonally crossing it are supported and fixed by the electrically conductive adhesive material 5. That is, it is taken into consideration that thickness- shear vibration waves vibrated at an excitation electrode provided on the crystal piece 6 are propagated in an X axis direction and propagated little to a Z axis direction, by supporting and fixing the Z axis direction, an effect to the thickness-shear vibration is made small. Also, in the case of supporting and fixing the crystal piece 6 on one side, the crystal piece 6 is supported and fixed to electrode pad parts 4 at two parts by the electrically conductive adhesive material and the thickness-shear vibration waves are small in the Z axis direction. Thus, the frequency is stabilized by the electrically conductive adhesive material 5. Then, by evacuating the inner part of the container, the gas inside the container is reduced and the frequency is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a crystal resonator required for a mobile communication device, particularly a frequency reference source of a mobile phone or a pager, and more specifically, it has a low series equivalent resistance and long-term stability of an oscillation frequency. The present invention relates to a highly accurate surface mount type crystal unit that has excellent heat resistance, reflow resistance and impact resistance, and enables a compact and thin structure.

[0002]

2. Description of the Related Art As a frequency reference source for mobile communication devices such as mobile phones, a highly accurate temperature-compensated crystal oscillator (hereinafter referred to as T
CXO) is used. In recent years, since the mobile communication devices are small and thin, the TCXO is also required to be small and thin, and the surface mount type with reflow resistance is required. Therefore,
In order to achieve these, the crystal oscillator, which is the main component of TCXO, must satisfy the characteristics, and a small and thin surface mount type crystal oscillator is required.

An AT-cut thickness slip oscillator is used as the crystal oscillator for TCXO. The required oscillator characteristics have a small frequency deviation at room temperature, excellent continuity in frequency temperature characteristics, and further are left at room temperature, high temperature, cold resistance, humidity resistance, temperature cycle, vibration, drop, and reflow resistance test. The rate of change of frequency is within ± 1 ppm.

In order to satisfy the above-mentioned strict characteristics and to achieve a surface-mount type crystal unit, selection of the package and sealing means, selection of the crystal axis of the crystal piece, appropriate design of the crystal piece size, and electrode material It is necessary to design a proper electrode shape, establish a crystal piece supporting method and process conditions.

The structure of the surface mount type crystal resonator in the prior art will be described with reference to FIGS. 15, 16, 18, and 19. FIG. 16 is a cross-sectional view showing a surface mount type crystal unit in which a seam welding means is used for hermetically sealing in the prior art.

As shown in FIG. 16, the first substrate 1 and the second substrate 1
The substrate 2 and the third substrate 3 are composed of a multi-layer ceramics substrate containing alumina as a main component. The electrode pad portion 4 on the second substrate 2 is formed by firing tungsten or molybdenum, plating nickel on it, and then gold plating on this nickel plating. A crystal piece 6 is supported and fixed to this electrode pad portion 4 by a conductive adhesive 5 on one side, and simultaneously with supporting and fixing, electrical connection is performed.

A seam ring 7 made of a Kovar alloy is brazed to the third substrate 3 by silver brazing, nickel plating is performed, and gold plating is further performed on the nickel plating. Furthermore, a lid 8 made of nickel plated Kovar alloy is hermetically sealed by a welding electrode 9 of a parallel seam welding machine, and the atmosphere in the container is nitrogen with a low dew point.

This surface mount type crystal oscillator has a nitrogen atmosphere in the container in order to keep the secular change of the frequency low, but the pressure is atmospheric pressure. Therefore, the crystal impedance of the crystal unit is about 13Ω to 15Ω.
Since the airtight sealing by the parallel seam welding is low-temperature bonding, there is an advantage that there is no problem of heat resistance of the conductive adhesive 5 and a wide range of selection is possible.

[0009]

However, the above-mentioned conventional surface mount type crystal unit has the following problems. FIG. 18 is a graph showing a secular change in frequency in a surface mount type crystal unit hermetically sealed by parallel seam welding in a nitrogen atmosphere. The horizontal axis represents the number of days the frequency was measured immediately after the hermetic sealing, and the vertical axis represents the frequency change rate. The required frequency change rate for one year is within ± 1 ppm.

The curve D is within the standard of the above-mentioned frequency change rate of plus or minus 1 ppm, but like the curve A and the curve B, the frequency shifts to plus or minus with time. In this way, it takes time to stabilize the frequency, and as a result, it is difficult for products that deviate from the standard to determine whether they are good or bad at the time of shipment. There is a problem that it comes out.

Next, problems of the conventional surface mount type crystal resonator will be described with reference to the plan view of FIG. 15 and the graph of FIG. FIG. 15 is a plan view showing a state in which the conductive adhesive 5 is formed on the surface mount type crystal unit.
A conductive adhesive 5 is formed on the electrode pad portion 4 for supporting and fixing the crystal piece 6. Since the crystal piece 6 is supported and fixed on one side, the region of the electrode pad portion 4 has a two-terminal structure.

The drop test result of the surface mount type crystal resonator using this means will be described with reference to the graph of FIG. The drop test condition is that the concrete is naturally dropped from a height of 1.5 m on the concrete, the horizontal axis shows the number of drops, and the vertical axis shows the frequency change rate. The standard of surface mount crystal unit is
As described above, it is within ± 1 ppm. A bar graph F shown by hatching is a drop test result of the surface mount type crystal resonator described with reference to FIGS. 15 and 16.

As shown in the graph of FIG. 19, the frequency change rate is ± 1 ppm up to 10 drop tests.
It is secured within. However, the drop test of 20 times greatly exceeds plus or minus 1 ppm. The cause will be described with reference to FIG. The electrode pad portion 4 is plated with gold, and the silicon-based conductive adhesive 5 is formed thereon. However, the adhesive force between the silicon, which is the conductive adhesive 5, and the gold of the electrode pad portion 4 is low. From this, the peeling phenomenon occurs at the interface between the two in the drop test of 20 times.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a surface mount type crystal resonator in which the secular change in frequency is stabilized early and the quality judgment is ensured. Further, in addition to the above-mentioned object of the invention, it is an object of the present invention to provide a surface mount type crystal resonator capable of reducing the frequency change rate in a drop test.

[0015]

In order to achieve the above object, the surface mount type crystal resonator of the present invention adopts the structure described below.

In the surface mount type crystal resonator of the present invention, one or both sides of both short side parts of the rectangular crystal piece are silicon-based, on the plane of the terminal member or in the recess.
A surface-mount type crystal unit in which a container is constructed by supporting and fixing it with a urethane-based or polyimide-based conductive adhesive, and airtightly joining a lid to the terminal member with an inorganic material, characterized in that the inside of the container is vacuum. And

The surface mount type crystal resonator according to the present invention is provided with a silicon-based or urethane-based one or both sides of both short sides of a rectangular crystal piece on the plane of the terminal member or in the recess.
Or fixed and supported with a polyimide-based conductive adhesive,
A surface mount type crystal unit, in which a lid is airtightly joined to a terminal member by solder to form a container, and the inside of the container is in a vacuum.

In the surface mount type crystal resonator of the present invention, one or both sides of both short sides of the rectangular crystal piece are silicon-based, on the plane of the terminal member or in the recess.
A surface-mount type crystal unit in which a urethane- or polyimide-based conductive adhesive is supported and fixed, and a lid is airtightly joined to the terminal member by seam welding to form a container, and the inside of the container is vacuum. And

In the surface-mount type crystal resonator of the present invention, the long side direction of the AT-cut rectangular crystal piece is the Z'axis on the plane of the terminal member or in the recess, and the X-axis direction is orthogonal thereto. A surface-mount type crystal unit in which both short sides are supported and fixed by a silicon-based or urethane-based conductive adhesive, and a lid is airtightly joined to the terminal member by solder to form a container. It is characterized by being.

In the surface mount type crystal resonator of the present invention, the long side direction of the AT cut rectangular crystal piece is defined as the Z'axis on the plane of the terminal member or in the recess, and the X axis direction is orthogonal thereto. A surface-mount type crystal unit in which both short sides are supported and fixed by a silicon-based or urethane-based conductive adhesive, and a lid is airtightly joined to the terminal member by seam welding to form a container. It is characterized by being a vacuum.

In the surface mount type crystal resonator of the present invention, the long side direction of the AT cut rectangular crystal piece is defined as the X axis on the plane of the terminal member or in the recess, and the Z'axis direction is orthogonal to the X axis. A surface-mount type crystal unit in which one side of the short side is supported and fixed by a silicon-based, urethane-based, or polyimide-based conductive adhesive, and a lid is airtightly joined to a terminal member by solder to form a container. The inside is characterized by a vacuum.

In the surface mount type crystal resonator of the present invention, the long side direction of the AT-cut rectangular crystal piece is defined as the X axis on the plane of the terminal member or in the recess, and the Z'axis direction is orthogonal to it. A surface-mount type crystal resonator in which one side of the short side portion is supported and fixed by a silicon-based, urethane-based, or polyimide-based conductive adhesive, and a lid is airtightly joined to the terminal member by seam welding to form a container, The inside of the container is characterized by a vacuum.

In the surface mount type crystal resonator of the present invention, one or both sides of both short sides of the rectangular crystal piece are silicon-based, on the plane of the terminal member or in the recess.
The shape of the electrode pad part of the crystal piece supporting and fixing part which is supported and fixed by a urethane or polyimide conductive adhesive is either a square or circular non-pad part in the electrode pad part or the electrode pad part Is a surface-mount type crystal resonator having a rectangular or circular non-pad portion at the end thereof, wherein the conductive adhesive is provided on both the electrode pad portion and the non-pad portion.

In the surface mount type crystal resonator of the present invention, one or both sides of both short sides of the rectangular crystal piece are silicon-based on the plane of the terminal member or in the recess.
The end electrode of the rectangular crystal piece, which is supported and fixed by a urethane or polyimide conductive adhesive and fixed to the electrode pad of the terminal member, has a rectangular or circular non-electrode part in the end electrode. Alternatively, a surface mount type crystal oscillator in which a rectangular or circular non-electrode part is provided at the end of the end electrode, wherein a conductive adhesive is provided on both the end electrode and the non-electrode part. .

In the surface mount type crystal resonator of the present invention, the material of the terminal member constituting the container is ceramics, glass ceramics, or glass.

In the surface mount type crystal resonator of the present invention, the material of the lid forming the container is characterized by being made of ceramics, glass ceramics, glass or metal.

In the surface mount type crystal resonator of the present invention, the material of the lid forming the container is made of metal, and the plating material formed on the metal is made of gold, palladium, or nickel and palladium. .

As described above, the surface mount type crystal resonator of the present invention adopts the above-mentioned structure, and the present invention improves the problems of the conventional technique from the following viewpoints. That is, for the purpose of early stabilization of frequency and confirmation of pass / fail judgment, the main means of solution is to use vacuum sealing from the structure of airtight bonding in a nitrogen atmosphere at atmospheric pressure, which is a conventional technology, Stabilize and ensure pass / fail judgment.

That is, when the pressure is atmospheric pressure, even if airtight bonding is performed in a nitrogen atmosphere, the gas generated during seam welding fills the container and it takes time to stabilize the atmosphere. further,
Stabilization of the frequency is impaired because the fine particles of the metal scattered during seam welding adhere to the quartz piece in an unstable state. As a result of their combination, it is considered that it takes time to stabilize the frequency after airtight bonding.

On the other hand, in the present invention, in the case of vacuum sealing, frequency stabilization can be realized at an early stage after airtight bonding. That is, it is considered that the gas generated by the airtight bonding is discharged to the outside of the container at a high rate because it is in vacuum. Therefore, the atmosphere in the container is stabilized early. As a result, the surface mount type crystal resonator of the present invention stabilizes the frequency quickly. The fact that the frequency is stabilized quickly has an effect that the quality can be determined at the time of shipment in a short time.

Further, in terms of ensuring the quality judgment, the crystal impedance of the crystal unit is 13 to 15Ω because the seam welding is airtight joining under atmospheric pressure.
However, although the crystal impedance does not change even if there is a minute leak, the frequency shifts after a long period of time. In other words, the atmosphere takes a long time to penetrate into the container. Therefore, a leak test is carried out with a helium leak tester at the time of shipment, but there is a problem that a minute leak that affects the change in frequency over time cannot be detected.

However, according to the vacuum sealing of the present invention, the crystal impedance is as low as 5 to 7Ω. In that case, if there is a minute leak, the crystal impedance increases immediately because it is sensitive to the pressure inside the container. Therefore, by determining the increase amount, it is possible to determine the presence or absence of leak, and as a result, the surface mount crystal resonator of the present invention can determine the frequency shift after a long period of time.

On the other hand, in order to reduce the frequency change rate in the drop test, the crystal piece is directly supported and fixed to the terminal member because it is a thin surface mount type crystal resonator. There are two types on both sides. In the present invention, a silicone-based conductive adhesive that is soft on both sides is used,
Frequency shift due to drop impact is reduced. That is, in the surface mount type crystal resonator of the present invention, a conductive adhesive having elasticity is used to relieve the mechanical stress caused by a drop impact. Further, the elasticity of the conductive adhesive is effective for relaxing the mechanical stress applied to the quartz crystal piece, and is therefore effective for the temporal change of the frequency.

However, even a soft silicone adhesive cannot be said to have high adhesion between the electrode pad portion of the terminal member and the gold of the end electrode of the crystal piece. Therefore, there is a problem that a strong drop impact causes a peeling phenomenon at the interface between the two and changes the frequency.

However, it has been confirmed that the silicon-based conductive adhesive has a strong adhesion between the ceramic of the terminal member and the crystal. Therefore, in the present invention, the ceramic is exposed on the surface of the electrode pad portion of the terminal member, and the crystal is exposed on the end electrode of the crystal piece. As a result, the silicon-based conductive adhesive improves not only the gold but also the ceramics and the crystal to improve the supporting and fixing force of the crystal piece, and the frequency change rate due to a drop impact is reduced in the present invention. It was done.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION A surface mount type crystal resonator according to the best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a state before a crystal piece is supported and fixed on both sides and a lid is airtightly joined in an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a state in which one side is supported and fixed and the lid is airtightly joined in the embodiment of the present invention. FIG. 3 is a plan view showing a state before airtightly joining the lid in FIG. 1 of the present invention. FIG. 4 is a plan view showing crystal axes of the crystal piece according to the present invention. 5, FIG. 6, FIG. 7, FIG. 8 and FIG.
10 and 10 are plan views showing various electrode pad portion shapes of the insulating terminal member in the embodiment of the present invention. Further FIG.
1, FIG. 12 and FIG. 13 are plan views showing various end electrode shapes of the crystal piece according to the embodiment of the present invention. FIG. 14 is a sectional view showing a structure in which an insulating terminal member according to the present invention and a crystal piece are combined and supported and fixed by a conductive adhesive. FIG.
FIG. 3 is a cross-sectional view showing a lid in the embodiment of the present invention. FIG. 20 is a sectional view showing a crystal oscillator. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 3, the first substrate 1, the second substrate 2, and the third substrate 3 form a terminal member. The crystal piece 6 is supported and fixed to the terminal member at both ends thereof. The electrode pad portion 4 and the airtight seal portion 10 are fired with tungsten or molybdenum on a terminal member formed of a multilayer ceramic substrate of the first substrate 1, the second substrate 2, and the third substrate 3, and nickel is deposited on the tungsten or molybdenum. It is plated and then gold plated.

In the embodiment of the present invention, the terminal member is described with ceramics containing alumina as a main component, but glass ceramics or glass may be applied. In the case of the terminal member made of glass ceramics, silver or a mixture of silver and palladium is used for the material of the electrode pad portion 4 and the airtight seal portion 10.

In the following description of the embodiments of the present invention, the terminal member will be described as a three-layer substrate, but a two-layer substrate in which the second substrate 2 is removed or a single-layer substrate may be used. Electrode pad portion 4 shown in FIG.
In this case, a silicon-based conductive adhesive 5 is formed and a crystal piece 6 is placed thereon. The conductive adhesive 5 may be a urethane adhesive. That is, a soft adhesive may be used.

Solder 11 is formed on the lid 8 shown in FIG. The detailed structure will be described with reference to the sectional view of FIG. The base material 12 of the lid shown in FIG. 17 is made of Kovar or an iron-nickel alloy, and has a two-layer structure of a nickel coating and a gold coating as the surface treatment film 13 on the Kovar or iron-nickel alloy.
Or a two-layer structure of nickel coating and palladium coating,
Or 2 of nickel coating and nickel palladium coating
Adopt a layered structure.

The nickel coating has a role of improving corrosion resistance, and the gold coating and the palladium coating have a role of improving wettability with the solder 11. Of these, the reason for using palladium is that it has the characteristics that there is little biting by the solder 11 and there is little airtight leak. The material of the solder 11 is gold (Au) -tin (Sn) or lead (Pb) -silver (Ag)-.
An alloy such as tin (Sn) or lead (Pb) -tin (Sn) is used. Other than the above, if it is a low temperature material capable of hermetically sealing, it can be applied as the solder 11.

Further, although the material of the lid 8 has been described as a metal material, ceramics, glass ceramics, or glass can also be applied. The terminal member and the lid 8 are preferably combined so that their thermal expansion coefficients match.

In FIG. 1, the solder 11 of the lid 8 is welded to the airtight seal portion 10 formed on the third substrate 3 in vacuum. If the solder 11 is gold (Au) -tin (Sn), the welding temperature is around 300 ° C., and the welding time is several minutes. In addition, welding work is performed using a heater substrate that can process a large number of pieces.

The embodiment shown in FIG. 2 has almost the same structure as the structure shown in FIG. 1, but the crystal piece 6 is supported and fixed on one side. Electrode pad portion 4 provided on the terminal member supporting one side thereof
Has two terminals on one side as shown in FIG. Further, the conductive adhesive 5 may be a silicone type or a polyimide type. Since the crystal piece 6 is supported and fixed on one side, a material slightly harder than silicon is used to enhance the support and fixing force.

The graph of FIG. 18 illustrates the secular change in frequency of the surface mount crystal unit according to the embodiment of the present invention described with reference to FIGS. 1, 2 and 3. The horizontal axis represents the number of days the frequency was measured immediately after the hermetic sealing, and the vertical axis represents the frequency change rate. The required frequency change rate for one year is within ± 1 ppm.

The surface mount type crystal unit hermetically sealed in the nitrogen atmosphere at atmospheric pressure by the conventional seam welding requires time to stabilize the frequency as shown by the curves A, B and D. However, in the surface mount type crystal resonator according to the present invention, as shown by the curve C, the frequency is stabilized early and the rate of change of the frequency in the long term is small. Further, the defective product is greatly deteriorated in a short period of time as shown by the curve E. That is, the quality becomes clear in a short period as compared with the conventional atmospheric pressure sealing. Therefore, the quality judgment can be made at an early stage at the time of shipping.

The surface mount type crystal unit according to the embodiment of the present invention has the following combinations to stabilize the frequency early and reduce the rate of change of the frequency in the long term. That is, by making the inside of the container a vacuum, the gas generated during the hermetic sealing is reduced. Further, as shown in FIGS. 2 and 3, when the crystal piece 6 is supported and fixed on both sides, the mechanical stress applied to the crystal piece 6 is relieved by using the soft silicon-based conductive adhesive 5. This is because the crystal piece 6 and the ceramics of the terminal member have different thermal expansion coefficients.

Further, as shown in FIG. 4, in the embodiment in which the crystal piece 6 is supported and fixed on both sides, the long side direction of the crystal piece 6 is Z '.
Both ends 15 composed of an axis and an X axis orthogonal to the axis are supported and fixed by a conductive adhesive 5. That is, by considering that the vibration wave of the thickness shear vibration vibrating by the excitation electrode 14 provided on the crystal element 6 propagates in the X-axis direction and the propagation to the Z′-axis is small, the Z′-axis direction is supported and fixed. The point is that the influence on thickness shear vibration is reduced.

On the other hand, when the crystal piece 6 is supported and fixed on one side shown in FIG. 2 contrary to the above, the crystal axis shown in FIG. 4 is reversed. That is, the long side direction is the X axis and the short side portion is Z '. In the case of one-sided support, two terminals are provided, and as shown in FIG. 9, the crystal piece 6 is supported and fixed to the two electrode pad portions 4 by the conductive adhesive 5. However, as described above, the vibration wave of the thickness shear vibration is Z ′. This is because it is small in the axial direction. Therefore, even with a conductive adhesive 5 that is slightly harder than a silicone adhesive such as a polyimide adhesive, the frequency can be similarly stabilized.

Although the embodiment of the present invention has been described by soldering, even the conventional seam welding method shown in FIG. 16 is vacuum sealing and uses a soft conductive adhesive. Further, if the supporting and fixing method uses a combination in which the crystal axis direction of the crystal piece is taken into consideration, the same effect as that described in the present invention can be obtained. In the seam welding method, gas is generated due to sparks during welding, but if airtight joining is performed while evacuating, the gas in the container is small and the frequency can be stabilized.

Next, an embodiment of the present invention for reducing the frequency change rate by a drop test will be described with reference to the drawings. In FIG. 1, a conductive adhesive 5 is formed on the electrode pad portion 4 and a crystal piece 6 is supported and fixed. The shape of the electrode pad portion 4 in the present invention will be described in order. FIG. 5 shows an embodiment in which a plurality of non-pad portions 16 each having a rectangular shape are alternately provided on the left and right ends of the electrode pad portion 4 on the second substrate 2. Although the rectangular shape is used in FIG. 5, it may be circular. The conductive adhesive 5 is provided on both the electrode pad portion 4 and the non-pad portion 16.

FIG. 6 shows an embodiment in which a single non-pad portion 16 having a square shape is provided at the end of the electrode pad portion 4. The non-pad portion 16 is made of the same ceramic as that of the second substrate 2.
Although the non-pad portion 16 is provided on the right side of the terminal member, it may be on the left side. Also in the case of the embodiment shown in FIG. 6, the conductive adhesive 5 is provided on both the electrode pad portion 4 and the non-pad portion 16.

FIG. 7 shows an embodiment in which a rectangular non-pad portion 16 is provided inside the electrode pad portion 4. Non-pad part 16
In addition to the square shape, the shape may be a circular shape or a plurality of shapes may be provided. FIG. 8 shows an embodiment in which a plurality of non-pad portions 16 each having a triangular shape are provided at the end of the electrode pad portion 4, and FIG. 9 shows an embodiment in which a plurality of non-pad portions 16 each having a circular shape are provided. Although described as circular in the embodiment of the present invention,
As described above, it may be a semicircle, and one having a curvature can be applied. Also, although a plurality of identical shapes are provided, a combination of different shapes may be used. In both cases, the conductive adhesive 5 is provided over both the electrode pad portion 4 and the non-pad portion 16. The area ratio between the electrode pad portion 4 and the non-pad portion 16 is preferably about 1: 1.

FIG. 10 shows an embodiment of the shape of the electrode pad when the crystal piece 6 as shown in FIG. 2 is supported and fixed on one side. Since the electrodes of the crystal piece 6 when supported and fixed on one side have two terminals on one side, the electrode pad portion also has two terminals on one side. A circular non-pad portion 16 is provided inside the electrode pad portion 4. It may have a rectangular shape instead of a circular shape. Further, as described above, the non-pad portion having various shapes may be provided at the end portion.

Further, an embodiment in the shape of the end electrode 15 of the crystal piece 6 in the case of being supported and fixed on both sides as shown in FIG. 1 will be described with reference to FIGS. 11, 12 and 13. FIG.
Reference numeral 1 shows an embodiment of the electrode shape of the crystal piece when it is supported and fixed on both sides. The excitation electrodes 14 are formed on the front and back sides and are led out as left and right end electrodes 15, respectively. The shape of the end electrode 15 is such that a non-electrode part 17 having a rectangular shape is provided at the end of the end electrode 15. The non-electrode part 17 is shown in FIG.
The number 1 is single, but a plurality may be used.

FIG. 12 shows an embodiment in which a plurality of non-electrode portions 17 each having a triangular shape are provided, and FIG. 13 shows an embodiment in which a plurality of non-electrode portions 17 each having a circular shape are provided. Although it is described as a circle in the embodiment of the present invention, it may be a semicircle like this, and one having a curvature is also applicable. Further, the non-electrode portions 17 are provided with a plurality of identical shapes, but a plurality of non-electrode portions 17 may be provided by combining different shapes. Further, as shown in FIG. 5, the shape of the non-electrode part 17 may be a left-right alternating shape.

As described above, the shape of the electrode pads provided on the terminal member and the shape of the end electrodes provided on the crystal piece have been described. The purpose thereof is to reduce the frequency change rate in the drop test. . This point will be described with reference to FIGS. 14 and 19.

FIG. 14 is a cross-sectional view showing a part of the embodiment of the present invention, in which a crystal piece is supported and fixed to a terminal member by a conductive adhesive. The electrode pad portion of the terminal member has the shape of the electrode pad portion 4 shown in FIG. Further, the crystal piece 6 adopts the shape of the end electrode 15 shown in FIG.

The electrode pad portion 4 and the non-pad portion 16 are provided on the second substrate 2, the crystal piece 6 further has the end electrodes 15 and the non-electrode portion 17, and the conductive adhesive 5 made of silicon is used. The excitation electrode 14 is formed between the two and electrically connected to the electrode pad portion 4. According to this structure, the conductive adhesive 5 is directly bonded not only to the electrode pad portion 4 and the end electrode 15, but also to the crystal piece 6 of the non-electrode portion 17 of the non-pad portion.

With such a structure, when the conductive adhesive 5 is supported and fixed, the adhesion is improved. As a result, crystal piece 6
The supporting and fixing force of is increased. The reason is that the surface of the electrode pad 4 is plated with gold, and the surface is smooth. For this reason, although the adhesive force may be weak depending on the type of material such as silicon and gold of the conductive adhesive 5, the adhesive force is also due to the fact that the surface roughness is small. On the other hand, the ceramic is exposed in the non-pad portion and the adhesion between the ceramic and silicon is good. In addition to that, there are many irregularities on the surface of the ceramic, and the conductive adhesive 5 bites into the irregularities to adhere. Power improves.

Further, with respect to the crystal piece 6, although the material of the excitation electrode 14 is Au, Pd, or Ag, the adhesion with silicon is not good as in the above case. However, as compared with the above, silicon has an excellent adhesion to the crystal surface of the non-electrode part 17.

As described above, the silicon-based conductive adhesive 5 has a sufficient adhesive force to the metal, but there is no problem in electrical connection. Therefore, the supporting and fixing force of the crystal piece 6 depends on the conductive adhesive 5.
It can be greatly improved by directly adhering to both ceramics and crystal, and the frequency change rate due to drop impact can be reduced.

The drop impact test result according to the embodiment of the present invention will be described with reference to the graph of FIG. The drop test condition is that the sample is naturally dropped on the concrete from a height of 1.5 m, the horizontal axis is the number of drops, and the vertical axis is the frequency change rate. The frequency change rate is within ± 1 ppm. The bar graph G is the result when the embodiment of the present invention is applied, and plus or minus 1 is obtained even after 20 drop impacts.
It is within the ppm, and the result is that it meets the standard.

FIG. 20 shows a crystal oscillator as an embodiment applied to another aspect of the present invention. The crystal oscillator is composed of a multilayer ceramic substrate, and wires are connected to the semiconductor chip 18. A crystal piece 6 is supported and fixed above the semiconductor chip 18 by a conductive adhesive 5. The supporting and fixing portion of the crystal piece 6 used at this time is the same as that in the case of the surface mount type crystal resonator described above. In other words, if the electrode pad shape of the terminal member and the end electrode shape of the crystal piece 6 are the same as those in the embodiment of the present invention, the drop impact resistance of the crystal oscillator is significantly improved.

[0065]

As is apparent from the above description, according to the present invention, it is possible to reduce the secular change in frequency itself of the surface mount type crystal unit. Furthermore, a minute leak can be determined by the change in crystal impedance, and the quality of the product can be determined early. In addition, since it is vacuum-sealed, the crystal impedance is low and the negative resistance of the oscillator can be large.

Further, according to the present invention, the drop impact resistance of the surface mount type crystal unit can be greatly improved. Therefore, in the prior art, the crystal piece is fixed to the support plate made of metal to absorb the shock, but such a support plate is not necessary and can be made thinner accordingly.

Furthermore, if the present invention is applied to a crystal oscillator, a thin product having excellent drop impact resistance can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of a surface mount type crystal resonator according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 3 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 4 is a plan view showing the structure of a surface mount type crystal resonator according to an embodiment of the present invention.

FIG. 5 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 6 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 7 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 8 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 9 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 10 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 11 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 12 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 13 is a plan view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 14 is a cross-sectional view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

FIG. 15 is a plan view showing a structure of a surface-mounted crystal resonator according to a conventional technique.

FIG. 16 is a cross-sectional view showing the structure of a surface-mount type crystal resonator according to a conventional technique.

FIG. 17 is a cross-sectional view showing the structure of the surface mount crystal resonator according to the embodiment of the present invention.

FIG. 18 is a graph showing a secular change in frequency of the surface mount crystal unit.

FIG. 19 is a graph showing a drop test result of the surface mount type crystal unit.

FIG. 20 is a cross-sectional view showing the structure of the surface mount type crystal resonator according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st board 2 2nd board 3 3rd board 4 Electrode pad part 5 Conductive adhesive agent 6 Quartz piece 8 Lid 10 Airtight seal part 11 Solder 12 Base metal 14 Excitation electrode 15 End electrode 16 Non-pad part 17 Non-electrode part 18 Semiconductor chip

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Murata, 840 Takeno, Shimotomi, Tokorozawa, Saitama Pref., CITIZEN WATCH CO., LTD. Address Citizen Watch Co., Ltd. Technical Research Institute (72) Inventor Takamasa Tanaka 4107, Miyota, Miyota-cho, Kitasaku-gun, Kitano, Nagano Prefecture 5 Miyota Co., Ltd. (72) Toshihide Oi 4107 Miyota, Miyota-cho, Kitasaku-gun, Nagano Prefecture 5 Within Miyota Co., Ltd.

Claims (14)

[Claims] 1. A flat or indented portion of a terminal member is supported and fixed on one or both sides of both short sides of a rectangular quartz piece with a silicon-based, urethane-based, or polyimide-based conductive adhesive, A surface-mount type crystal unit in which a lid is airtightly bonded to a terminal member with an inorganic material to form a container, and the inside of the container is in a vacuum. 2. One side or both sides of both short sides of a rectangular crystal piece are supported and fixed on a flat surface of a terminal member or in a recess with a silicon-based, urethane-based, or polyimide-based conductive adhesive, A surface-mount type crystal unit in which a lid is airtightly joined to a terminal member by soldering to form a container, and the inside of the container is a vacuum. 3. A flat or recessed portion of the terminal member is supported and fixed on one or both sides of both short sides of the rectangular crystal piece by a silicon-based, urethane-based, or polyimide-based conductive adhesive, A surface-mount type crystal unit in which a lid is airtightly joined to a terminal member by seam welding to form a container, and the inside of the container is a vacuum. 4. The A on the plane of the terminal member or in the recess.
The long side of the T-cut rectangular crystal piece is defined as the Z'axis, and both short sides of the X axis perpendicular to the Z'axis are supported and fixed by a silicon-based or urethane-based conductive adhesive, and the terminal member is covered. A surface-mount type crystal unit in which a container is air-tightly joined with solder to form a container, and the inside of the container is a vacuum. 5. The A on the plane of the terminal member or in the recess.
The long side direction of the T-cut rectangular crystal piece is defined as the Z'axis, and both short side parts in the X axis direction orthogonal to the Z'axis are supported and fixed with a conductive adhesive of urethane series or urethane series to form a terminal member. A surface-mount type crystal unit in which a lid is airtightly joined by seam welding to form a container, and the inside of the container is a vacuum. 6. A flat surface of the terminal member or in the recess
The X-axis is the long side direction of the T-cut rectangular crystal piece, and one side of the short side, which is the Z'-axis direction orthogonal to the X-axis, is silicon-based.
A surface-mount type crystal unit, which is supported and fixed by a urethane-based or polyimide-based conductive adhesive, and a lid is airtightly joined to a terminal member by solder to form a container, characterized in that the inside of the container is vacuum. Surface mount type crystal unit. 7. The A on the plane of the terminal member or in the recess.
The X-axis is the long side direction of the T-cut rectangular crystal piece, and one side of the short side, which is the Z'-axis direction orthogonal to the X-axis, is silicon-based.
A surface-mount type crystal unit in which a urethane- or polyimide-based conductive adhesive is supported and fixed, and a lid is airtightly joined to the terminal member by seam welding to form a container, and the inside of the container is vacuum. Surface mount type crystal unit. 8. A flat or recessed portion of a terminal member is supported and fixed on one or both sides of both short sides of a rectangular quartz piece by a silicon-based, urethane-based, or polyimide-based conductive adhesive. The shape of the electrode pad part of the crystal piece supporting and fixing part included in the terminal member is a surface mount type in which a square or circular non-pad part is provided in the electrode pad part or a square or circular non-pad part is provided at the end of the electrode pad part. A crystal resonator, wherein a conductive adhesive is provided on both the electrode pad section and the non-pad section. 9. A flat or indented portion of a terminal member is supported and fixed on one or both sides of both short sides of a rectangular quartz piece with a silicon-based, urethane-based, or polyimide-based conductive adhesive. The shape of the electrode pad part of the crystal piece supporting and fixing part included in the terminal member is a surface mount type crystal oscillator having a non-square or circular non-pad in the electrode pad part or a non-square or circular non-pad at the end of the electrode pad part. The conductive adhesive is provided on both the electrode pad portion and the non-pad portion.
The surface mount type crystal resonator according to 6 or 7. 10. The flat surface of the terminal member or in the recess,
The end of the rectangular crystal piece that is fixed to the electrode pad of the terminal member by supporting and fixing one or both sides of both short sides of the rectangular crystal piece with a silicon-based, urethane-based, or polyimide-based conductive adhesive The shape of the electrode is a surface mount type crystal oscillator in which a rectangular or circular non-electrode portion is provided inside the end electrode or a square or circular non-electrode portion is provided at the end portion of the end electrode. Is a surface-mount type crystal unit, which is provided on both end electrodes and non-electrode parts. 11. A flat surface of a terminal member or in a recess,
One or both sides of both short sides of the rectangular crystal piece are supported and fixed with a silicon-based, urethane-based, or polyimide-based conductive adhesive and fixed to the electrode pad of the terminal member. The shape of the end electrode is a surface mount type crystal oscillator in which a rectangular or circular non-electrode part is provided in the end electrode or a square or circular non-electrode part is provided at the end of the end electrode. An adhesive is provided on both the end electrodes and the non-electrode parts, wherein the adhesive is provided.
Alternatively, the surface mount crystal unit according to the item 8. 12. The material of the terminal member constituting the container is ceramics, glass ceramics, or glass, as claimed in claims 1, 2, 3, 4, 5, 6.
The surface mount type crystal resonator according to 7, 8, 9, 10 or 11. 13. The material of the lid constituting the container is ceramics, glass ceramics, glass, or metal, as claimed in claim 1, 2, 3, 4, 5, 6.
The surface mount type crystal resonator according to 7, 8, 9, 10 or 11. 14. The container constituting the container is made of metal, and the plating material formed on the metal is made of gold, palladium, or nickel and palladium. The surface mount crystal resonator according to 5, 6, 7, 8, 9, 10, or 11.